How do you transfer at Doha airport?

According to this video, when transiting at Doha Airport, you'll get a colour code on your boarding pass wallet: yellow for regular transfer in the main building, yellow with an orange edge for short Transfer in the main building, and green for transfer in the satellite building. There are then separate buses and bus stops depending on your colour.

One comment, however, states:

This video was made when the overcrowded old airport was in use. The new Hamad International Airport is open now, which works like any other airport - there are no special transfer procedures.

So, how does transfer at Doha currently work, with all possible scenarios combined where you have your onward boarding pass and want to get to your next gate directly?

If the colour system is still in place, how are you assigned a colour if checking in online and thus not going to a check-in desk?